Published online May 28, 2013. doi: 10.3748/wjg.v19.i20.3150
Revised: February 3, 2013
Accepted: February 28, 2013
Published online: May 28, 2013
Processing time: 171 Days and 17.4 Hours
AIM: To investigate the effects of Lactobacillus plantarum (L. plantarum) CAI6 and L. plantarum SC4 on hyperlipidemic mice.
METHODS: Male Kunming mice were fed a high-cholesterol diet for 28 d to construct hyperlipidemic models. Hyperlipidemic mice and normal mice were assigned to 3 groups which were separately treated with L. plantarum CAI6, L. plantarum SC4, and physiological saline through oral gavage for 28 d. Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) levels were measured by commercially available enzyme kits. FACS Calibur flow cytometry was used to examine hepatic and renal nuclear factor-erythroid 2-related factor 2 (Nrf2) expression. The morphology of livers was checked by hematoxylin and eosin staining and optical microscope observation.
RESULTS: Compared with normal mice, hyperlipidemic mice possessed significantly higher TC (3.50 ± 0.43 vs 2.89 ± 0.36, P < 0.01), TG (1.76 ± 0.07 vs 1.10 ± 0.16, P < 0.01), and LDL-C (1.72 ± 0.20 vs 0.82 ± 0.10, P< 0.01) levels, resulting in an increase of atherogenic index (AI) (2.34 ± 1.60 vs 0.93 ± 0.55, P < 0.05) and LDL-C/HDL-C ratio (1.43 ± 0.12 vs 0.51 ± 0.16, P < 0.05). After treatment with L. plantarum CAI6/L. plantarum SC4, TG (1.43 ± 0.27/1.54 ± 0.10 vs 1.76 ± 0.07, P < 0.01/P < 0.05) and LDL-C (1.42 ± 0.07/1.47 ± 0.12 vs 1.72 ± 0.20, P < 0.01/P < 0.01) in hyperlipidemic mice significantly decreased. In addition, TC, HDL-C, AI, and LDL-C/HDL-C ratio were all positively changed. Meanwhile, the treatment markedly alleviated hepatic steatosis and significantly stimulated Nrf2 expression (73.79 ± 0.80/72.96 ± 1.22 vs 54.94 ± 1.84, P < 0.01/P < 0.01) in hepatocytes of hyperlipidemic mice.
CONCLUSION: L. plantarum CAI6 and L. plantarum SC4 may protect against cardiovascular disease by lipid metabolism regulation and Nrf2-induced antioxidative defense in hyperlipidemic mice.
Core tip: Protective effects of Lactobacillus plantarum (L. plantarum) CAI6 and L. plantarum SC4 strains on hyperlipidemic mice were found, including regulating lipid metabolism, alleviating hepatic steatosis and reducing cardiovascular disease (CVD) risk. The mechanism of intracorporal antioxidation of Lactobacillus strains may be related to stimulation of nuclear factor-erythroid 2-related factor 2 (Nrf2) expression. Hypolipidemic effect and Nrf2-induced antioxidative defense may contribute to the reduction of CVD risk. We suggest that food fermented by the strains be used as part of the diet to relieve lipid metabolism related metabolic syndrome and to reduce the risk of CVD.